Subaru 2002 IMPREZA Service Manual page 1549

5. Stall Test
A: INSPECTION
1. GENERAL INFORMATION
The stall test is of extreme importance in diagnos-
ing the condition of the automatic transmission and
the engine. It should be conducted to measure the
engine stall speeds in "R" and "2" ranges.
Purposes of the stall test:
1) To check the operation of the automatic trans-
mission clutch.
2) To check the operation of the torque converter
clutch.
3) To check engine performance.
2. TEST METHODS
1) Preparations before test:
(1) Check that throttle valve opens fully.
(2) Check that engine oil level is correct.
(3) Check that coolant level is correct.
(4) Check that ATF level is correct.
(5) Check that differential gear oil level is cor-
rect.
(6) Increase ATF temperature to 50 to 80°C
(122 to 176°F) by idling the engine for approx.
30 minutes (with select lever set to "N" or "P").
2) Install an engine tachometer at a location visible
from the driver's compartment and mark the stall
speed range on the tachometer scale.
3) Place the wheel chocks at the front and rear of
all wheels and engage the parking brake.
4) Move the manual linkage to ensure it operates
properly, and shift the select lever to the "2" range.
5) While forcibly depressing the foot brake pedal,
gradually depress the accelerator pedal until the
engine operates at full throttle.
(A) Brake pedal
(B) Accelerator pedal
6) When the engine speed is stabilized, read that
speed quickly and release the accelerator pedal.
7) Shift the select lever to "N" range, and cool down
the engine by idling it for more than one minute.
8) Record the stall speed.
STALL TEST
9) If the stall speed in "2" range is higher than spec-
ifications, low clutch slipping and 2-4 brake slipping
may occur. To identify it, conduct the same test as
above in "D" range.
10) Perform the stall tests with the select lever in
"R" range.
NOTE:
• Do not continue the stall test for MORE THAN 5
SECONDS at a time (from closed throttle, fully
open throttle to stall speed reading). Failure to fol-
low this instruction causes the engine oil and ATF
to deteriorate and the clutch and brake to be ad-
versely affected.
Be sure to cool down the engine for at least 1
minute after each stall test with the select lever set
in the "P" or "N" range and with the idle speed lower
than 1,200 rpm.
• If the stall speed is higher than the specified
range, attempt to finish the stall test in as short a
time as possible, in order to prevent the automatic
transmission from sustaining damage.
Stall speed (at sea level):
1.6 L model: 2,200 — 2,700 rpm
2.0 L Non-turbo model: 2,000 — 2,500 rpm
2.0 L Turbo model: 2,600 — 3,300 rpm
2.5 L model: 2,100 — 2,600 rpm
B3M1589B
AT-13
AUTOMATIC TRANSMISSION